Slitter and stacker for sheet metal blanks

ABSTRACT

A stacker at the output of a rotary knife slitter for sheet metal blanks receives the output blanks in corresponding slots formed by thin sheet metal partitions maintained under tension at the ends. Long blanks are stacked in accurate register at high speed without twisting or jamming in the stacking slots.

United States Patent David A. Strilich Inventor Hobart, Ind.

Appl. No. 20,908

Filed Mar. 19, 1970 Patented Oct. 12, 1971 Assignee Gary Steel Products Corp.

Gary, Ind.

SLITTER AND STACKER FOR SHEET METAL BLANKS 5 Claims, 6 Drawing Figs.

U.S. Cl 83/89, 83/92, 83/94, 214/6 D Int. Cl B65h 29/52 Field of Search 83/86, 89, 92, 94; 214/6 D, 6 H, 6 S

References Cited UNITED STATES PATENTS 2,504,228 4/1950 Sandberg et a1. 83/86 X 3,079,150 2/1963 Lopez 214/6 D X 3,411,389 11/1968 Wiese 83/94 3,550,493 12/1970 Benbenek et a1. 83/94 Primary Examiner-William S. Lawson Attorney-Leonard G. Nierman ABSTRACT: A stacker at the output of a rotary knife slitter for sheet metal blanks receives the output blanks in corresponding slots formed by thin sheet metal partitions maintained under tension at the ends. Long blanks' are stacked in accurate register at high speed without twisting or jamming in the stacking slots.

PATENTED um 1 219m SHEET 2 [1F 2 INVENTOR.

DA W0 A. STR/L/CH SLITTER AND STACKER FOR SHEET METAL BLANKS This invention relates to machinery for slitting of sheet metal and more particularly to machinery for slitting sheets into blanks which are thereupon deposited in parallel stacks.

A multiple knife or gang slitter is employed for longitudinal division of sheets into strips for a variety of purposes. ln general utility gang slitters, the rotary slitting knives are laterally adjustable in position, so that input sheets are longitudinally cut in any desired number of pieces of selected width. The blanks are desirably collected in output stacks arranged side-by-side in general correspondence with their relative positioning upon emergence from the slitter. The present invention employs a simple form of stacker for achieving this with a multiple gang slitter producing an output in the form of a substantial number of elongated parallel strips.

In the stacking device of the invention, as in certain constructions which are found unsatisfactory for the purpose, simple dividers or partitions are aligned with each pair of the rotary knives of the slitter, thus forming output slots or stacking receptacles into which the respective parallel elongated strips are deposited in the same relative orientation in which they are ejected from the slitter. In accordance with the invention in its broader aspects, the partitions are formed of long thin sheets, preferably of steel of a thickness of from 0.005 inch to 0.05 inch, which are held under tension at the forward and rearward ends to maintain them in rigid and straight position along the line of each cut. Warping and bending of partitions, which can occur with long use of thicker, and thus superficially stronger, partitions, is substantially eliminated as a problem by occasional retensioning adjustment if necessary. At the same time, the thin partitions can be individually adjusted in alignment with the knives in each new set up without the experimentation or calculation which is found necessary in setting partitions of a thickness substantially greater than the small spacing between the blanks produced by the operation of rotary slitter knives. In addition, the use of very thin partitions greatly reduces problems of jamming and improper stacking which are encountered with partitions of sufficient thickness to be rigid without the exertion of tension at the ends, without any necessity for spreading or fanning out of the blanks as they leave the slitter head.

The invention in -its narrower aspects provides an adjustment and tensioning construction for such partitions which is both simple in construction and convenient for use in set up. In the preferred form of the invention, the partitions form open bottom slots, and there is provided therebeneath a vertically reciprocable support table which is wholly elevated at the beginning of a slitter run and is lowered as the run proceeds. The run is terminated at a point when the table remains above its lowermost position, and the further lowering of the table then frees the stacks from the stacking slots. The support table may be used with suitable pallets, which may thus be removed and replaced preparatory to the next run of blanks. The loaded pallets thus bear the stacks of blanks in substantially the same volume as that of the sheets from which they were cut.

These and further objects and advantages of the invention, and the manner in which they are achieved, will be better understood from description of the embodiment illustrated in the drawing, in which:

FIG. 1 is a top plan view of slitter machinery (the slitter itself being shown only schematically) embodying the invention;

FIG. 2 is a view in side elevation of the machinery of H0. 1;

FIG. 3 is a fragmentary perspective view showing one of the dividers or separators employed in the structure of FIG. 1, along with associated portions of the structure;

HO. 4 is a longitudinal sectional view of portions of the assembly of FIG. 3 taken along the line 44 of that figure;

F IG. 5 is a fragmentary elevational view of an end portion of a divider prior to the right angle bending of its ear portions; and

FIG. 6 is a sectional view taken along the line 6-6 in FIG. 4.

The embodiment illustrated consists. of a multigang slitter mechanism generally indicated at 10 and a stacker generally indicated at 12, disposed to receive the output from the slitter 10.

The slitter 10 is illustrated only fragmentarily and schematically, constituting in itself no novel aspect of the invention. For present purposes it need merely be stated that it has a substantial number of rotary knife sets 14 laterally adjustable on shafts 16 (only the upper shaft being visible in the drawing) to slit input sheet metal along the lines fixed by the adjustable positioning. It is also required, for best utilization of the invention, that the separation of the blanks performed by the slitter be linear along the entire length, and the slitter construction is preferably one which produces such action in the slitting of sheets without manual guidance by an operator.

In the illustrated embodiment, the stacker 12 is disposed immediately at the output of the slitter 10. However, if so desired, the output of the slitter 10 may be delivered to a belt or similar conveyor which receives the slitted sheets and thereafter feeds them to the stacker with unaltered relative positions. Such an intermediate conveyor is affirmatively desirable where the operating speed of the slitter itself is insufficient to eject the slitted stock with sufficient inertia to assure that the trailing end will not stop short of entering the desired position in the stacker.

The stacker 12 has a floor-supported base 18 provided with suitable uprights 20 which support an upper rectangular frame having side portions 22 and 24 and front and rear end portions 26 and 28. (For convenience, the end adjacent the slitter output will herein be called the front.) Across the top extends a dual carriage, generally indicated at 30. The carriage 30 is longitudinally adjustable in position on suitable tracks atop the respective side members 22 and 24. The position of the carriage is manually adjusted in accordance with the length of the blanks being processed. This position is manually locked by a handwheel 32 on the front portion 34 of. the dual carriage, the rear portion 36 being reciprocable during the slitter operation to produce longitudinal register of the stacking as later discussed.

Extending along the length of the frame, between the end members 26 and 28, are parallel partition or separator members 38, each being substantially exactly aligned with the interface of a pair of the knives or shears l4, and thus coinciding with the respective slits of the blanks ejected from the slitter head. The construction of these partitions or separators and the manner in which they are supported and adjusted are shown in FIGS. 3 through 6.

The body portion of each of the partitions or separators consists of an elongated rectangular strip 40 of relatively thin sheet material. A highly desirable stock for the purpose is galvanized steel of from 0.005 to 0.05'inch thickness. For example, dividers or partitions of 24 gauge galvanized steel of six inch width have been found highly suitablefor use in a stacker capable of accommodating blanks of upto 13 feet in length. Although the invention may be utilized in stackers of more limited length capacity, it is particularly advantageous wherever stock of length substantially greater than about five feet is to be accommodated. The front end portion 26 of the frame is formed by an upper compound bar or beam 42 and a lower compound bar or beam 44 having facing flat surfaces and each formed from suitable bar and tube stock. The back frame member 28 is similarly formed byupper and lower beams 46 and 48. Flat mounting blocks 50 are laterally slideable between the respective pairs of flat surface beams. From the outer ends of the blocks 50 extend threaded studs 52-. Holding plates 54 at respective ends have rectangular inner portions 56 likewise slideable between the beams and flanged or enlarged outer portions 58 abutting against the outer surfaces .of the beams. The bolts or studs 52.are passedby central apertures 60 in the holding plates 54 and tightening nuts 62 engage-their ends.

To the inner surfaces of each pair of respectively corresponding blocks 50 at opposite endsv of the frame is secured, by bolts 64, a partition or separator assembly comprising clamping bars 66 holding each end of the separator or divider 40. Each end of the separator is clamped between a pair of bars 66 by bolts 70, the separator being apertured at 72 to pass the bolts. To further maintain the security of clamping, ear portions 74 are formed at the ends of the separator, with 90 bends (shown by dotted line 75 in FIG. 5) engaging the clamp.

Each separator 40 is readily released for positioning by loosening of the nut 62 at one end. In this loosened condition, each of the mounting blocks may be independently adjusted in lateral position to correspond with a shear line, and tightening thereupon produces wholly linear alignment of the upper edge of the separator or divider partition, along with vertical planar alignment. Any slight bending or waviness which may develop in one or more partitions with long use may, if desired, be eliminated by increasing the tension to the point of stretching. The simple partitions may, however, be readily replaced if required.

In the lower portion of the stacker, a roller table 80 is suitably mounted for vertical motion (mounting and drive omitted in the drawing) between an upper position wherein a pallet placed thereon is disposed at the lower edge of the partitions 40 and a lowermost position wherein the roller table 80 is at the same level as an output conveyor 82. The roller table is appropriately elevated at the commencement of each slitter run, gradually lowered (either stepwise or continuously) to maintain the upper portions of the stacks at an appropriate level as the run proceeds, and dropped to the lowermost level at the end of the run for removal of the pallet bearing the output.

As each set of blanks is ejected from the slitter (or from an intermediate conveyor), it is deposited in the slot formed by an adjacent pair of separators 40. The velocity is sufficient so that the trailing edge of the blank goes beyond the clamps 66. The rearward end of each of the slots is formed by a backstop plate 84, Each backstop plate is supported by a bar 86, at the upper end of which is a slider 88 mounted on a common transverse track 90 which extends across the top on the reciprocable portion 36 of the dual carriage earlier described A pneumatic cylinder mechanism 92 interconnects the two portions of the carriage 30. After each reception of a set of slitted blanks (or at greater intervals if so desired) the pneumatic mechanism 92 is actuated to pull the backstop members 84 forward and produce alignment of the stacks against the clamps 66, which thus also serve as front end-stops for longitudinal alignment of the blanks. In the construction illustrated, the lower ends of the clamps 66 extend a small distance downward beyond the lower edges of the separator partitions 40. This construction assures that the proper longitudinal alignment produced in the top portion of the stacks is not altered by frictional displacement of the lower portion of the stacks.

With the construction illustrated, the slitter stock is stacked on a pallet in substantially the same configuration as a stack of input stock, with individual stacks separated just enough to prevent frictional engagement of the lateral edges, which are sometimes rough. The pallet (or two or more pallets where required) is normally loaded with the ends of the blanks extending beyond the pallet edges for ease of subsequent individual handling of the stacks. Where so desired, appropriate sheets or strips may be inserted between adjacent stacks to maintain the alignment where, for example, the loaded pallet is to be shipped or similarly handled in a manner otherwise altering the precise stacking arrangement.

It will be obvious that many of the construction details of the embodiment illustrated in the drawing and described above in accordance with the patent laws may be greatly varied while nevertheless utilizing the teachings of the invention in both its broader and narrower aspects. Accordingly, the scope of the protection to be afforded the invention should not be considered to be limited by the particular embodiment illustrated and described,

What is claimed is: 1, ln machinery for multiple slitting and stacking of sheet metal blanks comprising a gang slitter and a stacker receiving the output of the slitter, the improved construction wherein the stacker comprises vertical sheet metal partitions of a thickness of from 0.005 to 0.05 inch each aligned along a slitting line and having means for holding the partitions under tension at the ends.

2. The construction of claim 1 wherein the holding means for a partition comprises a pair of clamping members on opposite faces of the end of the partition to thus serve also as end-stops for stacked blanks.

3. The construction of claim I having a vertically reciprocable table beneath the lower edges of the partitions.

4. The construction of claim 2 wherein the clamping members extend downwardly below the lower edges of the partitions to prevent frictional displacement of lower portions of stacks.

5. The construction of claim 2 having mounting and tensioning means for the clamping members including spaced parallel horizontal beams, a flat surfaced block secured to the clamping members and slideably disposed between the beams, and threaded locking and tensioning means acting between the block and the outer surfaces of the beams. 

1. In machinery for multiple slitting and stacking of sheet metal blanks comprising a gang slitter and a stacker receiving the output of the slitter, the improved construction wherein the stacker comprises vertical sheet metal partitions of a thickness of from 0.005 to 0.05 inch each aligned along a slitting line and having means for holding the partitions under tension at the ends.
 2. The construction of claim 1 wherein the holding means for a partition comprises a pair of clamping members on opposite faces of the end of the partition to thus serve also as end-stops for stacked blanks.
 3. The construction of claim 1 having a vertically reciprocable table beneath the lower edges of the partitions.
 4. The construction of claim 2 wherein the clamping members extend downwardly below the lower edges of the partitions to prevent frictional displacement of lower portions of stacks.
 5. The construction of claim 2 having mounting and tensioning means for the clamping members including spaced parallel horizontal beams, a flat surfaced block secured to the clamping members and slideably disposed between the beams, and threaded locking and tensioning means acting between the block and the outer surfaces of the beams. 